Assembly and system including a tibial cut guide

ABSTRACT

A system that can be used in a knee replacement procedure can include a tibial cut guide and an alignment guide. The tibial cut guide can have a first guide portion coupled to and adjustable relative to a second guide portion. The first guide portion can be configured to define a sagittal cut slot and a proximal cut slot. The alignment guide configured for extramedullary mounting to the patient and configured to couple with the second guide portion of the tibial cut guide, the alignment guide having a first mechanism and a second mechanism of differing construction, the first mechanism and the second mechanism are both configured to be actuated to facilitate extension and retraction of the alignment guide to position the tibial cut guide in a desired proximal-distal location relative a tibia of a patient when the tibial cut guide and the alignment guide are assembled together.

CLAIM OF PRIORITY

This application is a continuation-in-part and claims the benefit ofpriority to U.S. patent application Ser. No. 15/266,311, filed Sep. 15,2016, which is hereby incorporated by reference in its entirety.

FIELD

The present subject matter relates to orthopedic procedures and, moreparticularly, to an assemblies and systems that can aid in boneresection for knee arthroplasties.

BACKGROUND

Orthopedic procedures and prostheses are commonly utilized to repairand/or replace damaged bone and tissue in the human body. For example, aknee arthroplasty can be used to restore natural knee function byrepairing damaged or diseased articular surfaces of the femur and/ortibia. An incision is made into the knee joint to expose the bonescomprising the joint. Cut guides are used to guide the removal of thearticular surfaces that are to be replaced. Prostheses are used toreplicate the articular surfaces. Knee prostheses can include a femoralcomponent implanted on the distal end of the femur, which articulateswith a tibial component implanted on the proximal end of a tibia toreplicate the function of a healthy natural knee. Various types ofarthroplasties are known including a total knee arthroplasty, where allof the articulating compartments of the joint are repaired withprosthetic components.

OVERVIEW

The present inventors recognize the need for an extramedullary alignmentguide that can be used to quickly and accurately position (with regardto proximal-distal location, varus-valgus location, sagittal cut angleand medial-lateral location, and/or posterior slope angle) a tibial cutguide for removal of the articular surfaces of the tibia. The presentinventors also recognize that the alignment guide can be provided afeature to make small adjustments to the proximal-distal location of thetibial cut guide once the alignment guide has already been fixated tothe tibia can further reduce procedure time and improve accuracy. Theinventors further recognize that the tibial cut guide can have aseparate second portion defining a sagittal cut slot. This secondportion can be adjustable relative to a remainder of the tibial cutguide (and indeed the alignment guide) to adjust a location and rotationangle of the sagittal cut. The tibial cut guide with the adjustableportion can allow for adjustment of the location and rotation angle ofthe sagittal cut after determining a desired proximal-distal location,varus-valgus location, and/or posterior slope angle for the tibial cutguide. This can allow for quicker and simpler adjust of the tibia cutguide to a desired position to perform resection. Further, the inventorsrecognize the need to adjust a proximal-distal position of the tibialcut guide in a rapid manner. Thus, one or more connections betweenportions of the alignment guide can be “quick-connect” or“quick-release” in nature to facilitate quick and accurate assembly,disassembly, positioning, and repositioning of the alignment guide andtibial cut guide.

To further illustrate the apparatuses and systems disclosed herein, thefollowing non-limiting examples are provided:

In Example 1, a system for a knee replacement surgery that canoptionally comprise: a tibial cut guide having a first guide portionconfigured to couple with and be adjustable relative to a second guideportion, wherein the first guide portion is configured to define asagittal cut slot and a proximal cut slot; and an alignment guideconfigured for extramedullary mounting to the patient and configured tocouple with the second guide portion of the tibial cut guide, thealignment guide having a first mechanism and a second mechanism ofdiffering construction, the first mechanism and the second mechanism areboth configured to be actuated to facilitate extension and retraction ofthe alignment guide to position the tibial cut guide in a desiredproximal-distal location relative a tibia of a patient when the tibialcut guide and the alignment guide are assembled together.

In Example 2, the system of claim 1, wherein the first guide portion canbe insertable in and moveable within a track defined by the second guideportion.

In Example 3, the system of any one or any combination of Examples 1-2,wherein the first guide portion can be rotatable relative to the secondguide portion about a proximal-distal axis to adjust an angle of one ormore of the sagittal cut slot and the proximal cut slot with respect toan anterior-posterior axis.

In Example 4, the system of Example 3, wherein the angle can be between±1°, 3°, 5°, 6° up to 100 relative to the anterior-posterior axis.

In Example 5, the system of any one or any combination of Examples 1-4,wherein the first guide portion can be adjustable such that a positionof the sagittal cut slot and the proximal cut slot can be changedmedial-lateral.

In Example 6, the system of Example 5, wherein the position can bechanged medial-lateral by ±1.0, 3.0, 5.0 mm up to 10 mm relative to azero offset position.

In Example 7, the system of any one or any combination of Examples 1-6,wherein the first guide portion and the second guide portion can haveindicia to indicate one or more of a degree of angulation and a degreeof offset positioning between the first guide portion and the secondguide portion.

In Example 8, the system of Example 7, wherein the degree of angulationcan be indicative of a medial-lateral angle of the sagittal cut slotrelative to an anterior-posterior axis.

In Example 9, the system of any one or any combination of Examples 1-8,wherein the first guide portion can have a male projection configured tobe captured within a medial-lateral extending slot defined by the secondguide portion, and wherein when the male projection is captured thefirst guide portion has some degree of freedom to rotate about aproximal-distal axis relative to the second guide portion.

In Example 10, the system of any one or any combination of Examples 1-9,wherein the sagittal cut slot can communicate with an aperture, andwherein the aperture is configured to receive a fastener therein to fixthe first guide portion relative to the tibia and the second guideportion.

In Example 11, the system of any one or any combination of Examples1-10, wherein the proximal cut slot can be offset from a mount of thesecond guide portion in at least one of a medial or lateral directionand the proximal cut slot is configured to define a medial-lateral cutlength such that the proximal cut is to a single compartment of a knee.

In Example 12, an apparatus for guiding a tibial bone cut during kneereplacement surgery, the apparatus can optionally comprise: a firstguide portion, wherein the first guide portion is configured to define asagittal cut slot and a proximal cut slot; a second guide portion havinga mount configured to couple with an alignment guide; wherein the firstguide portion is couple with and is adjustable relative to the secondguide portion to change one or more of a medial-lateral position of thesagittal cut slot and an angle of the sagittal cut slot relative to ananterior-posterior axis.

In Example 13, the apparatus of Example 12, wherein the first guideportion is insertable in and moveable within a track defined by thesecond guide portion.

In Example 14, the apparatus of any one or any combination of claims12-13, wherein the first guide portion can be rotatable relative to thesecond guide portion about a proximal-distal axis to adjust the angle ofthe sagittal cut slot and the proximal cut slot with respect to theanterior-posterior axis.

In Example 15, the apparatus of Example 14, wherein the angle can bebetween ±1°, 3°, 5°, 6° up to 10° relative to the anterior-posterioraxis.

In Example 16, the apparatus of any one or any combination of claims12-15, wherein the first guide portion is adjustable such that aposition of both the sagittal cut slot and the proximal cut slot can bechanged medial-lateral.

In Example 17, the apparatus of Example 16, wherein the position can bechanged medial-lateral by ±1.0, 3.0, 5.0 mm up to 10 mm relative to azero offset position.

In Example 18, the apparatus of any one or any combination of claims12-17, wherein the first guide portion and the second guide portion canhave indicia to indicate one or more of a degree of angulation and adegree of offset positioning between the first guide portion and thesecond guide portion.

In Example 19, the apparatus of Example 18, wherein the degree ofangulation can be indicative of a medial-lateral angle of the sagittalcut slot relative to the anterior-posterior axis.

In Example 20, the apparatus of any one or any combination of claims12-19, wherein the first guide portion can have a male projectionconfigured to be captured within a medial-lateral extending slot definedby the second guide portion, and wherein when the male projection iscaptured the first guide portion has some degree of freedom to rotateabout a proximal-distal axis relative to the second guide portion.

In Example 21, the apparatuses and systems of any one or any combinationof Examples 1 to 20 can optionally be configured such that all elementsor options recited are available to use or select from.

These and other examples and features of the present apparatuses andsystems will be set forth in part in the following Detailed Description.This Overview is intended to provide non-limiting examples of thepresent subject matter—it is not intended to provide an exclusive orexhaustive explanation. The Detailed Description below is included toprovide further information about the present apparatuses and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralscan describe similar components in different views. Like numerals havingdifferent letter suffixes can represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various examples discussed in the presentdocument.

FIG. 1 is a front elevation view of a tibia and a femur showing axes ofthe knee joint according to an example of the present application.

FIG. 2 is an elevated perspective view of the tibia and femur showingvarious axes of the knee joint according to the example of the presentinvention.

FIG. 3 is a perspective view of a disassembled extramedullary tibialalignment guide according to an example of the present invention.

FIG. 4 is a perspective view of the tibial alignment guide being used toposition a tibial cut guide relative to a tibia of a patient ofaccording to an example of the present application.

FIG. 5A is a perspective view of an anterior side of a proximal assemblyof the tibial alignment guide of FIG. 3 according to an example of thepresent application.

FIG. 5B is a perspective view of a posterior side of a proximal assemblyof the tibial alignment guide of FIG. 5A according to an example of thepresent application.

FIG. 6A is a perspective view of a first mechanism of at a distal end ofthe proximal assembly of the tibial alignment guide of FIGS. 5A and 5Baccording to an example of the present application.

FIG. 6B is an exploded view of the first mechanism of FIG. 6A accordingto an example of the present application.

FIG. 7 is an enlarged view of the proximal assembly of the tibialalignment guide showing a second mechanism according to an example ofthe present application.

FIG. 7A is exploded view of the second mechanism in isolation from theremainder of the tibial alignment guide according to an example of thepresent application.

FIG. 7B is a cross-sectional view of the second mechanism according toan example of the present application.

FIG. 7C is a perspective view of a distal assembly of the secondmechanism showing a ball plunger extending at least partially thereformaccording to an example of the present application.

FIG. 7D is a perspective view with portions of the second mechanismremoved to show the orientation of the ball plunger relative to thetibial alignment guide according to an example of the presentapplication.

FIG. 8A is a perspective view of a tibial cut guide locking mechanism ofthe alignment guide according to an example of the present application.

FIG. 8B is a cross-sectional view of the tibial cut guide lockingmechanism of FIG. 8A according to an example of the present application.

FIG. 8C is a plan view with portions of a housing of the tibial cutguide locking mechanism removed to illustrate a body component residingtherein according to an example of the present application.

FIG. 9 shows a tibial cut guide disposed adjacent the tibial alignmentguide and configured to be coupled therewith according to an example ofthe present application.

FIG. 10A-10D are views of the tibial cut guide of FIG. 9 from variousperspectives according to an example of the present application.

FIGS. 11A-11D are views of a second tibial cut guide from variousperspectives according to another example of the present application.

DETAILED DESCRIPTION

The present application relates to devices and systems for kneereplacement procedures. For example, the present application discloses atibial alignment guide that can position a tibial cut guide for removalof the articular surfaces of the tibia.

FIG. 1 illustrates various axes of the lower limb in the frontal plane.Axes can be defined for each segment of the lower limb. For example, afemur 10 has an anatomic axis 32 coinciding generally with itsintramedullary canal. It also has a mechanical axis 34, or load axis,running from the center of the femoral head to the center of the knee.The angle 36 between these two axes 32, 34 in the frontal plane varieswithin the patient population but is on the order of 4-9°. The two axes32, 34 are approximately superimposed in the sagittal plane. Likewise, atibia 12 has a mechanical axis 38 coinciding generally with itsintramedullary canal. The mechanical axis 38 of the tibia 12 runs fromthe center of the knee to the center of the ankle. The transverse axis,or joint line 39, about which the knee flexes, is parallel to a linethrough the medial and lateral femoral condyles and parallel to thetibial plateau. Typically, the distal femur and proximal tibia areresected to be parallel to the joint line 39, and thus perpendicular tothe mechanical axes 34, 38 as indicated at 40 and 42. The intersectionof the femoral and tibial mechanical axes 34, 38 may subtend a smallangle relative to one another. However, the angle can be small such thatthe axes 34, 38 are approximately collinear and may be treated ascollinear for most purposes.

A distal femoral cut can be made perpendicular to the femoral axes 32,34 in the sagittal plane. A proximal tibial resection is typically cutto match the natural posterior slope of the proximal tibia in thesagittal plane, relative to the mechanical axes 34, 38. The amount ofposterior to anterior slope (also referred to herein as posterior slopeangle) relative perpendicular to the mechanical axes 34, 38 varies inthe patient population but is on the order of 2° to 7°. The distancebetween the distal femoral cut and proximal tibial cut along themechanical axes 34, 38 is the extension gap. Other cuts may be madedepending on the components that are to be implanted and the type ofprocedure performed.

As used herein, “proximal” refers to a direction generally toward thetorso of a patient, and “distal” refers to the opposite direction ofproximal, i.e., away from the torso of a patient. “Anterior” refers to adirection generally facing away from the patient, i.e. toward thesurgeon performing the surgery, and “posterior” refers to the oppositedirection of anterior, i.e., toward the front (anterior) of a patient orknee. In the context of the tibial alignment guide and tibial cut guidesuch as those disclosed herein, such directions correspond to theorientation of these when in use (i.e. when mounted to or adjacent thepatient in an operable position to assist in making desired resections),such that a proximal assembly of the assembly is that portion which willordinarily be closest to the torso of the patient, the anterior portionclosest to the surgeon, the posterior portion generally closest to theanterior portion of the patient's knee, etc.

FIG. 2 depicts six aspects of component positioning relative to acoordinate system in which the x-axis 70 (media-lateral axis)corresponds approximately to the joint line 39, the z-axis 72(proximal-distal axis) corresponds approximately to the mechanical axes34 and 38, and the y-axis 74 (anterior-posterior axis) is normal to theother two. Position along each of these axes is depicted by arrows.Position along the x, y, and z axes determines the medial-lateral (dx)76, anterior-posterior (dy) 78, and proximal-distal (dz) 80 positioningof components respectively. Rotation about each of these axes is alsodepicted by arrows. Rotation about the z-axis (rz) 82 correspondsanatomically to external rotation of the femoral component, rotationabout the x-axis (rx) 84 corresponds to extension plane rotation, androtation about the y-axis (ry) 86 corresponds to varus/valgus rotation.

FIG. 3 shows a system 100 according to one example of the presentdisclosure. When assembled the system 100 can comprise a tibialalignment guide 102 configured for extramedullary mounting to a patient.The system 100 can include an ankle clamp 104, a distal assembly 106, aproximal assembly 108, a first mechanism 110 and a second mechanism 112.The proximal assembly 108 includes a first body 114 and a second body116.

As shown the ankle clamp 104 can be configured to connect to the distalassembly 106. The distal assembly 106 can be adjustableanterior-posterior relative to the ankle clamp 104. The distal assembly106 can have a portion extending generally proximal-distal whenassembled. The proximal assembly 108 can be configured to be mounted onand moveable relative distal assembly 106. For example, the proximalassembly 108 can receive the portion of the distal assembly 106 and canbe adjustable generally proximal-distal relative to the distal assembly106 via actuation of the first and/or second mechanisms 110, 112 as willbe discussed subsequently. Such adjustment of the proximal assembly 108can allow the tibial alignment guide 102 to be extended and retracted toposition a tibial cut guide in a desired proximal-distal locationrelative a tibia of a patient when the tibial cut guide and thealignment guide 102 are assembled together as will be further discussedsubsequently.

The ankle clamp 104 can be configured with spring arms 118 adapted toclamp around an ankle of the patient such as proximal to the malleoli.The ankle clamp 104 can include a rod 120 that can have one or moreengagement features (e.g., threads, slots, detents, teeth, etc.) alongat least a portion thereof. The distal assembly 106 can be configured toreceive the rod 120 therein. The distal assembly 106 can have a thirdmechanism 122 that can receive the rod 120 therein. The third mechanism122 can be configured as a quick connect to couple with the one or moreengagement features to fixedly connect the distal assembly 106 to theankle clamp 104. The third mechanism 122 can be configured to beactuated by the user to disengage the third mechanism 122 from theengagement feature(s) to allow for adjustment of the position of thedistal assembly 106 relative to the ankle clamp 104. Such adjustment canbe facilitated by depressing and holding a button or similar feature ofthe third mechanism 122, for example.

As shown in the example of FIG. 3, the distal assembly 106 can include arod 124 configured to extend generally proximal-distal when assembledwith the ankle clamp 104. The rod 124 can have one or more engagementfeatures 126 (e.g., threads, slots, detents, teeth, etc.) along at leasta portion thereof. The proximal assembly 108 can include a slot 128(FIG. 5B) configured to receive at least a part of the rod 124 therein.

As shown in FIGS. 3 and 5A, the first mechanism 110 can be carried bythe proximal assembly 108 at a distal portion thereof, for example. Thefirst mechanism 110 that can receive the rod 124 (FIG. 3) therein. Thefirst mechanism 110 can be configured to couple with the one or moreengagement features 126 (FIG. 3) to fixedly connect the proximalassembly 108 to the distal assembly 106. The first mechanism 110 can beconfigured to be actuated by the user to disengage the first mechanism110 from the one or more engagement features 126 (FIG. 3) to allow foradjustment of the position of the proximal assembly 108 generallyproximal-distal relative to the distal assembly 106. Such adjustment canbe facilitated by depressing and holding a button 130 or similar featureof the first mechanism 110, for example.

In the example of FIGS. 3 and 5A, the proximal assembly 108 can becomprised of the first body 114 and the second body 116. The proximalassembly 108 (in particular the second body 116) can also include an arm131 extending proximally. The arm 131 can be configured to receive afastener (not shown) or other component therein to couple the tibialalignment guide 102 to the tibia of the patient. The second body 116 cancarry the first mechanism 110. The second mechanism 112 can be receivedwithin a recess 132 (FIG. 5A) of the second body 116 proximal of thefirst mechanism 110. The second mechanism 112 can be carried on thefirst body 114, and indeed can be threadably engaged thereto withinter-engaging threads as will be discussed subsequently.

The first body 114 can be moveable relative to the second body 116 bythe second mechanism 112. Such movement of the first body 114 relativeto the second body 116 can facilitate extension and retraction of thetibial alignment guide 102 to position the tibial cut guide in a desiredproximal-distal location relative a tibia of a patient when the tibialcut guide and the alignment guide 102 are assembled together. FIGS. 3and 5A show an example where the first mechanism 110 and the secondmechanism 112 can be of differing construction (i.e. have differentstructure and operate according to different principles when actuated).

As shown in FIG. 4, the first mechanism 110 and the second mechanism 112can both be configured to be actuated to facilitate generallyproximal-distal movement of tibial alignment guide 102. In particular,the first mechanism 110 and the second mechanism 112 can both beconfigured to be actuated to facilitate extension and retraction of thetibial alignment guide 102 to position the tibial cut guide 134 in adesired proximal-distal location relative a tibia 136 of a patient whenthe tibial cut guide 134 and the tibial alignment guide 102 areassembled together.

As shown in FIGS. 5B and 6A, the proximal assembly 108 can include theslot 128 configured to receive at least a part of the rod 124 (FIG. 3)of the distal assembly 106 (FIG. 3) therein. The first mechanism 110 canbe configured to engage with the one or more engagement features 126(e.g., threads, slots, detents, teeth, etc.) along at least a portion ofthe rod 124 (FIG. 3). This engagement can create a fixed connectionbetween the proximal assembly 108 and the distal assembly 106 until thefirst mechanism 110 is disengaged by actuation by the user.

As shown in FIGS. 6A and 6B, the first mechanism 110 can comprise thebutton 130, a spring 138 and a housing 140. The housing 140 can definean opening 142 to the slot 128.

The housing 140 can be configured to receive the rod 124 (FIG. 3)therethrough via the opening 142 defined by the housing 140. The rod 124(FIG. 3) can be T-shaped to match the slot 128 (FIG. 5B) and opening 142according to one example. The housing 140 can further include an openend that is configured to receive a portion of the button 130 therein.The spring 138 (e.g., a conical compression spring) can be positionedbetween an end portion 144 (FIG. 6B) of the button 130 and an interiorsurface of the housing 140. As shown in FIG. 6B, the button 130 candefine an interior passage 146 proximal of and communicating with theopening 142. The interior passage 146 can be provided with threading 148configured to engage with the one or more engagement features 126 of therod 124 (FIG. 3).

The button 130 can be configured to be depressible to facilitateadjustment of the proximal assembly 108 relative to the distal assembly106. As previously discussed, the button 130 can be configured to engagethe one or more engagement features 126 (FIG. 3) of the distal assembly106 (FIG. 3). The configuration of the first mechanism 110 canfacilitate fast assembly and adjustment of the tibial cut guide to adesired position. Upon release of the button 130, the spring 138 canpush the inner threading 148 of the interior surface of the interiorpassage 146 into engaging contact with the one or more engagementfeatures 126 of the rod 124 (FIG. 3) to lock the position of theposterior assembly 108 (and in particular the second body 116) relativeto the distal assembly 106 (FIG. 3).

FIG. 7 shows an enlargement of a portion of the proximal assembly 108and the second mechanism 112. As shown in FIG. 7, the second mechanism112 can comprise a thumb screw 150 configured to threadably engage (withthreading 151 shown in FIGS. 7A and 7B) the first body 114 and bereceived within the recess 132 of the second body 116.

As shown in FIGS. 7A to 7C, the thumb screw 150 can be configured toretain one or more ball plunger assemblies 152 therein such that only aball portion 154 of the one or more ball plunger assemblies 152 canprotrude from a distal surface 156 of the thumb screw 150.

In FIG. 7D, the thumb screw is removed to illustrate the positioning ofthe one or more ball plunger assemblies 152 within the recess 132 of thesecond body 116 about the first body 114. As shown in the example ofFIG. 7D, the second body 116 can configured with one or more grooves 158that are configured to interact with the one or more ball plungerassemblies 152 (in particular the ball portion 154) to act as indicia ofa degree of movement of the second mechanism 112 and an amount ofproximal-distal travel of the first body 114 relative to the second body116. For example, the one or more grooves 158 and the one or more ballplunger assemblies 152 can interact to make a clicking noise to indicate90 degrees of rotational movement of the second mechanism 112, andfurther, the clicking noise can indicate 1 mm of proximal-distal travelof the first body 114 relative to the second body 116.

FIG. 8A shows a proximal portion 160 of the proximal assembly 108. Asshown in FIG. 8A, the first body 114 can include a coupling mechanism162. The second body 116 can include the arm 131 extending proximallyand having the through hole 133 configured to receive a fastener. Asshown in the example of FIG. 8A, both the first body 114 and the secondbody 116 can have indicia 163A and 163B, respectively. When usedtogether, the indicia 163A and 163B are indicative of an amount ofproximal-distal travel of the first body 114 relative to the second body116. According to one example, the indicia 163A can comprise a referenceline while the indicia 163B can comprise a series of 1.0 mm separatedlines and additionally a reference line 164 indicating a neutralposition. As shown in FIG. 8A, the indicia 163B can indicate ±5.0 mmrelative to the neutral position. The indicia 163A and 163B can be usedwith adjustment of the first body 114 relative to the second body 116using the second mechanism 112 (FIGS. 7A-7D) after pinning the secondbody 116 to the tibia via through hole 133 as previously discussed.

The coupling mechanism 162 is configured to engage with and be actuatedto couple the tibial cut guide 134 (FIGS. 4 and 9 to 10D). The couplingmechanism 162 shown in FIG. 8A includes a slot 166 and pin 168 and isfurther illustrated and described with reference to FIGS. 8B and 8C. Theslot 166 can allows for an amount of proximal-distal travel of the pin168 as will be discussed subsequently. Coupling mechanisms that may beconstructed and/or operate in a similar manner as the coupling mechanism162 are described in United States Patent Application Pub. 2013/0204260,U.S. patent application Ser. No. 15/184,016, and U.S. Provisional PatentApplication Ser. No. 62/254,474, the entire disclosures of which areincorporated herein by reference.

Turning to FIG. 8B, the coupling mechanism 162 can include a housing170, a body component 172, a spring 174, a lever 176, a member 178 andfirst and second pins 168, 182. The body component 172 of the couplingmechanism 162 can include first and second slots 184, 186 (only shown inFIG. 8C).

As illustrated in FIG. 8B, the housing 170 can comprise a hollowcontainment member having openings at both the proximal end and a distalside thereof. The body component 172 can reside therein, and can have aconic head portion 188 that extends therefrom on a proximal end. As willbe discussed, the body component 172 can be moveable relative to thehousing 170 in a constrained manner. The spring 174 can be positionedwithin the body component 172 (between the first pin 168 and an inferiorsurface of a head of the member 178). The member 178 can be contacted ona superior surface of the head by the surfaces of lever 176. The lever176 can extend from the distal side opening of the housing 170 and adistal side opening of the body component 172 as shown in FIG. 8B a. Thesecond pin 182 can be can be received in an aperture or slot of the bodycomponent 172. The first pin 168 can be received in the slot 168 of thehousing 170 and can be received in the first slot 184 of the bodycomponent 172.

In operation, the lever 176 can be actuated upward (pivoting about thefirst pin 168) away from the position shown in FIGS. 8A to 8C to unlockthe coupling mechanism 162 to facilitate removal of and/or addition ofthe tibial cut guide, which is mounted to a conic head portion 188.Movement of the lever 176 can allow the body component 172 to betranslated upward relative to the housing 170. The spring 174 may not beconstrained until the first pin 168 contacts the proximal end of theslot 166 in the housing 170. With movement of the body component 172proximally, the conic head portion 188 has sufficient clearance relativeto a proximal end portion of the housing 170 such that a mating femaleconic portion of the tibial cut guide can be mounted to the bodycomponent 172 and the housing 170. When the lever 176 is pivoted back tothe distal position illustrated in FIGS. 8A to 8C, a conic lock betweenthe cut guide and the conical head portion 188 is maintained by thespring 174 such that the male conic portion 188 is in fully engagedcontact and is seated with the female conic portion located on thetibial cut guide. The projection 190 extending proximally from theproximal end of the housing 170 can be configured to fit in a femalecounterpart slot or recess in the tibial cut guide. In this manner, thebody component 172 and the housing 170 can constrain the proximal-distaland rotational movement of the tibial cut guide.

FIG. 9 shows a system 200 including the tibial cut guide 134 and thetibial alignment guide 102 as previously discussed. The tibial cut guide134 can include a mount 202 configured to couple with the male conicportion 188 of the tibial cut guide 102 as previously described.

The tibial cut guide 134 is further illustrated in reference to FIGS.10A to 10D. The tibial cut guide 134 can include a first guide portion204 and a second guide portion 206.

The mount 202 can connect to and indeed can be formed as port of thesecond guide portion 206. The first guide portion 204 can be coupled toand can be adjustable relative to the second guide portion 206. Thefirst guide portion 204 can configured to define a sagittal cut slot208. The second guide portion is configured to define a proximal cutslot 210. The sagittal cut slot 208 and the proximal cut slot 210 areconfigured to limit travel and orient a sagittal resection and aproximal resection, respectively, when performed on the tibia. Such cutscan be performed using known cutting tools. According to the example ofFIGS. 10A to 10D, the tibial cut guide 134 can be configured forresection of a single compartment of the tibia. More particularly, theproximal cut slot 210 can be offset from the mount 202 of the secondguide portion 206 in at least one of a medial or lateral direction. Theproximal cut slot 210 can be configured to define a medial-lateral cutlength such that the proximal cut is to a single compartment of a knee.

As shown by arrows in FIG. 10B, the first guide portion 204 can beconfigured to be adjustable both with respect to a medial-lateralposition (as shown by arrow ML) and a rotational position (as shown byarrow A about proximal-distal axis PD) relative to the second guideportion 206. Changing the rotational position of the first guide portion204 can change the angle of the sagittal cut slot 208 from the neutralposition shown in FIGS. 10B (indicated with line NA) and 10C such thatthe sagittal cut slot 208 can be angled (i.e. canted) to extend, amedial-lateral distance, a proximal-distal distance and ananterior-posterior distance. In the neutral position, the sagittal cutslot 208 can be oriented to extend substantially only theproximal-distal distance and anterior-posterior distance. The change inangle can be of varying degree as desired. The angle of the sagittal cutslot 208 can be changed ±1°, 3°, 5°, 6° up to 10° relative to theneutral position (the position where the sagittal cut 208 is alignedwith an anterior-posterior axis AP) shown in FIGS. 10B and 10C, forexample. Similar, the position of the sagittal cut slot 208 can bechanged medial-lateral by ±1.0, 3.0, 5.0 mm up to 10 mm relative to theneutral position shown in FIGS. 10B and 10C.

FIGS. 10B and 10C further show that the second guide portion 206 candefine a recess 212 relative to the proximal cut slot 210. The recess212 can be configured to receive the first guide portion 204 therein.The recess 212 can be open along a portion of the medial-lateral lengththereof, but can be at least partially defined by along such length byanterior-posterior spaced projections 214A, 214B configured to receive apin 216 therein. The first guide portion 204 can be configured with aleg 218 that can be configured to insert between the anterior-posteriorspaced projections 214A, 214B and beneath the pin 216. The tibial cutguide 200 can be configured with some degree of freedom between the leg218, the anterior-posterior spaced projections 214A, 214B, and the pin216 to allow for the adjustment of the rotational position and/or themedial-lateral position of the first guide portion 204 relative to thesecond guide portion 206 as previously described.

As shown in FIGS. 10A and 10C, the sagittal cut slot 208 can communicatewith an aperture 220. The aperture 220 can be configured to receive afastener therein to fix the first guide portion 204 relative to thetibia and the second guide portion 206. The fastener or other feature,when received in the aperture 220, can act as a stop for a cutting toolmaking a sagittal resection of the tibia.

FIGS. 11A to 11D show a tibial cut guide 334 that can be used as analternative to the tibial cut guide 134 of FIGS. 9-10D. The tibial cutguide 334 can include a first guide portion 304 and a second guideportion 306. In particular, FIG. 11A shows an assembly of the firstportion 304 and the second portion 306 coupled together. FIGS. 11B and11C show exploded views of the first portion 304 separated from thesecond portion 306. FIG. 11D show a view of distal parts of the firstportion 304 and the second portion 306.

The second guide portion 306 can include a mount 302 (FIGS. 11A-11C)similar to those previously described. The first guide portion 304 canbe coupled to and can be adjustable relative to the second guide portion306. The first guide portion 304 can configured to define both asagittal cut slot 308 and a proximal cut slot 310 as shown in FIGS.11A-11C. The sagittal cut slot 308 and the proximal cut slot 310 areconfigured to guide, limit travel and orient a sagittal resection and aproximal resection, respectively, when performed on the tibia. Such cutscan be performed using known cutting tools. According to the example ofFIGS. 11A to 11D, the tibial cut guide 334 can be configured forresection of a single compartment of the tibia. More particularly, theproximal cut slot 310 can be offset from the mount 302 of the secondguide portion 306 in at least one of a medial or lateral direction. Theproximal cut slot 310 can be configured to define a medial-lateral cutlength such that the proximal cut is to a single compartment of a knee.

As shown by arrows in FIGS. 11A-11D, the first guide portion 304 can beconfigured to be adjustable both with respect to a medial-lateralposition (as shown by arrow ML in FIGS. 11A-11D) and a rotationalposition (as shown by arrow A in FIGS. 11B-11D about a proximal-distalaxis PD) relative to the second guide portion 306. Changing therotational position of the first guide portion 304 can change the angleof the sagittal cut slot 308 from the neutral position shown in FIG. 11Asuch that the sagittal cut slot 308 can be angled (i.e. canted) toextend, a medial-lateral distance, a proximal-distal distance and ananterior-posterior distance. Thus, the sagittal cut slot 308 can beangled relative to the anterior-posterior axis AP of FIG. 11A. In theneutral position of FIG. 11A, the sagittal cut slot 308 can be orientedto extend substantially only the proximal-distal distance andanterior-posterior distance. The change in angle can be of varyingdegree as desired. The angle of the sagittal cut slot 308 can be changed±10, 3°, 5°, 6° up to 10° relative to the neutral position (the positionwhere the sagittal cut 308 is aligned with an anterior-posterior axisAP) shown in FIG. 11A, for example. Similar, the position of thesagittal cut slot 308 can be changed medial-lateral by ±1.0, 3.0, 5.0 mmup to 10 mm relative to a zero offset position (a position where thesagittal cut slot 308 is aligned with the mount 302 in a proximal-distalmanner) of the shown in FIG. 11A.

Additionally, the angle and medial-lateral position of the proximal cutslot 310 can be adjusted with the configuration of the tibial cut guide334, as the proximal cut slot 310 is defined by the moveable first guideportion 304. Thus, the angle of the proximal cut slot 310 can be changed±1°, 3°, 5°, 6° or more relative to the neutral position shown in FIG.11A, for example. Similar, the position of the proximal cut slot 310 canbe changed medial-lateral by ±1.0, 3.0, 5.0 mm or more relative to thezero offset position shown in FIG. 11A.

As show in FIG. 11A the first guide portion 304 and the second guideportion 306 can be provided with indicia 311A, 311B, respectively. Theseindicia 311A and 311B can be used to provide an indication of the amountof medial-lateral offset between the first guide portion 304 and thesecond guide portion 306. The indicia 311A and 311B can also indicatethe degree of the angle formed between the first guide portion 304 andthe second guide portion 306.

FIGS. 10B and 10C further show that the second guide portion 306 canhave a slot 312 that defines a track 314 for the first guide portion 304that allows the first guide portion 304 to be moved medial-lateralrelative to the second guide portion 306 in a defined manner. The slot312 can be configured to receive a male projection 316 of the firstguide portion 304 therein. The slot 312 can have an opening 318 along afirst portion 319 of the medial-lateral length thereof. The opening 318can be configured to allow insertion of the male projection 316 into theslot 312. The slot 312 can than narrow relative to the opening 318 alonga second portion 321 of the medial-lateral length thereof. This narrowsecond portion 321 can be configured to capture the male projection 316to limit proximal-distal movement and couple the first guide portion 304with the second guide portion 306.

More particularly, as shown in FIG. 11D, the male projection 316 canhave a distal end section 320 with a relatively larger cross-sectionalarea and an intermediate section 322 with a relatively smallercross-sectional area. As shown in FIG. 11D, this intermediate section322 can be configured to be captured by the second portion 321 of theslot 312 but can be sized to allow some degree of play (degree offreedom) to allow for pivoting of the first guide portion 304 relativeto the second guide portion 306 to allow for change in the position andangle of the sagittal cut slot 308 (FIGS. 11A-I 1C) and the proximal cutslot 310 (FIGS. 11A-11C) as discussed above. The distal end section 320can be sufficient large in cross-section to inhibit removal of the firstguide portion 304 from the second guide portion 306 when the maleprojection 316 is in the second portion 321 of the slot 312.

As shown in FIGS. 11A-11C, the sagittal cut slot 308 can communicatewith an aperture 324. The aperture 324 can be configured to receive afastener therein to fix the first guide portion 304 relative to thetibia and the second guide portion 306, if desired. The fastener orother feature, when received in the aperture 324, can act as a stop fora cutting tool making a sagittal resection of the tibia

With reference to the FIGURES presented herein, a method for performinga tibial knee resection is also disclosed herein. The method can includemounting a tibial cut guide to an alignment mechanism. The tibial cutguide can be configured to facilitate both a proximal cut and a sagittalcut to a tibia. The method can adjust a proximal-distal location andvarus-valgus location for a first slot that is used to define theproximal cut. A first portion of the alignment guide can be fixated tothe tibia of the patient. Such step of fixation can occur afteradjusting the proximal-distal location and varus-valgus location for thefirst slot as desired according to one example. After fixating the firstportion of the alignment guide to the tibia, the method can adjust aproximal-distal height of the cut guide by extending or retracting asecond portion of the alignment guide relative to the first portion ofthe alignment guide. Such extending and retracting can be in a generallyproximal-distal direction according to one example. After adjusting theproximal-distal height of the cut guide, the method can adjust at leastone of a medial-lateral location and a rotational angle of a second slotof the tibial cut guide that is used to define the sagittal cut bymoving a first guide portion of the tibial cut guide relative to asecond guide portion with reference to one or more anatomical landmarksof the knee. According to some examples, after adjusting the at leastone of the medial-lateral location and the rotational angle of thesecond slot that can be used to define the sagittal cut, the method canfixate the first guide portion to the tibia prior to resecting thetibia. Resection of the tibia can be accomplished by performing both theproximal cut and the sagittal cut utilizing the tibial cut guide. Theanatomical landmarks used with the method can include one or more of theintercondylar eminence of the tibia, a connection position of an ACLwith the tibia, a medial third of a tubercle at insertion of a PCL, andan intercondylar geometry of a femur according to one example.

ADDITIONAL NOTES

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) can be used in combination with each other. Otherexamples can be used, such as by one of ordinary skill in the art uponreviewing the above description. The Abstract is provided to comply with37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain the natureof the technical disclosure. It is submitted with the understanding thatit will not be used to interpret or limit the scope or meaning of theclaims. Also, in the above detailed description, various features can begrouped together to streamline the disclosure. This should not beinterpreted as intending that an unclaimed disclosed feature isessential to any claim. Rather, inventive subject matter can lie in lessthan all features of a particular disclosed example. Thus, the followingclaims are hereby incorporated into the detailed description as examplesor embodiments, with each claim standing on its own as a separateexample, and it is contemplated that such examples can be combined witheach other in various combinations or permutations. The scope of theinvention should be determined with reference to the appended claims,along with the full scope of equivalents to which such claims areentitled.

The claimed invention is:
 1. A system for a knee replacement surgerycomprising: a tibial cut guide having a first guide portion configuredto couple with and be adjustable relative to a second guide portion,wherein the first guide portion is configured to define a sagittal cutslot and a proximal cut slot; and an alignment guide configured forextramedullary mounting to the patient and configured to couple with thesecond guide portion of the tibial cut guide, the alignment guide havinga first mechanism and a second mechanism of differing construction, thefirst mechanism and the second mechanism are both configured to beactuated to facilitate extension and retraction of the alignment guideto position the tibial cut guide in a desired proximal-distal locationrelative a tibia of a patient when the tibial cut guide and thealignment guide are assembled together.
 2. The system of claim 1,wherein the first guide portion is insertable in and moveable within atrack defined by the second guide portion.
 3. The system of claim 1,wherein the first guide portion is rotatable relative to the secondguide portion about a proximal-distal axis to adjust an angle of one ormore of the sagittal cut slot and the proximal cut slot with respect toan anterior-posterior axis.
 4. The system of claim 3, wherein the angleis between +1°, 3°, 5°, 6° up to 10° relative to the anterior-posterioraxis.
 5. The system of claim 1, wherein the first guide portion isadjustable such that a position of the sagittal cut slot and theproximal cut slot can be changed medial-lateral.
 6. The system of claim5, wherein the position is changed medial-lateral by +1.0, 3.0, 5.0 mmup to 10 mm relative to a zero offset position.
 7. The system of claim1, wherein the first guide portion and the second guide portion haveindicia to indicate one or more of a degree of angulation and a degreeof offset positioning between the first guide portion and the secondguide portion.
 8. The system of claim 7, wherein the degree ofangulation is indicative of a medial-lateral angle of the sagittal cutslot relative to an anterior-posterior axis.
 9. The system of claim 1,wherein the first guide portion has a male projection configured to becaptured within a medial-lateral extending slot defined by the secondguide portion, and wherein when the male projection is captured thefirst guide portion has some degree of freedom to rotate about aproximal-distal axis relative to the second guide portion.
 10. Thesystem of claim 1, wherein the sagittal cut slot communicates with anaperture, and wherein the aperture is configured to receive a fastenertherein to fix the first guide portion relative to the tibia and thesecond guide portion.
 11. The system of claim 1, wherein the proximalcut slot is offset from a mount of the second guide portion in at leastone of a medial or lateral direction and the proximal cut slot isconfigured to define a medial-lateral cut length such that the proximalcut is to a single compartment of a knee.
 12. An apparatus for guiding atibial bone cut during knee replacement surgery, the apparatuscomprising: a first guide portion, wherein the first guide portion isconfigured to define a sagittal cut slot and a proximal cut slot; asecond guide portion having a mount configured to couple with analignment guide; wherein the first guide portion is couple with and isadjustable relative to the second guide portion to change one or more ofa medial-lateral position of the sagittal cut slot and an angle of thesagittal cut slot relative to an anterior-posterior axis.
 13. Theapparatus of claim 12, wherein the first guide portion is insertable inand moveable within a track defined by the second guide portion.
 14. Theapparatus of claim 12, wherein the first guide portion is rotatablerelative to the second guide portion about a proximal-distal axis toadjust the angle of the sagittal cut slot and the proximal cut slot withrespect to the anterior-posterior axis.
 15. The apparatus of claim 14,wherein the angle is between ±1°, 3°, 5°, 6° up to 10° relative to theanterior-posterior axis.
 16. The apparatus of claim 1, wherein the firstguide portion is adjustable such that a position of both the sagittalcut slot and the proximal cut slot can be changed medial-lateral. 17.The apparatus of claim 16, wherein the position is changedmedial-lateral by ±1.0, 3.0, 5.0 mm up to 10 mm relative to a zerooffset position.
 18. The apparatus of claim 12, wherein the first guideportion and the second guide portion have indicia to indicate one ormore of a degree of angulation and a degree of offset positioningbetween the first guide portion and the second guide portion.
 19. Theapparatus of claim 18, wherein the degree of angulation is indicative ofa medial-lateral angle of the sagittal cut slot relative to theanterior-posterior axis.
 20. The apparatus of claim 12, wherein thefirst guide portion has a male projection configured to be capturedwithin a medial-lateral extending slot defined by the second guideportion, and wherein when the male projection is captured the firstguide portion has some degree of freedom to rotate about aproximal-distal axis relative to the second guide portion.